The Red Guy is the main antagonist of the Cow and Chicken series and also appears in it's spin-off I Am Weasel as both the tritagonist and sometimes as one of the two main antagonists (alongside I.R. Baboon).
He was voiced by legendary voice actor Charlie Adler, who also played Gazeem in Disney's Aladdin, Snively in the Sonic the Hedgehog SatAM TV show, Ed Bighead in Rocko's Modern Life, Hamilton in Disney's Tarzan, Starscream in the Transformers film series.
Appearance
The Red Guy is an overweight and naked red creature who resembles classical depictions of devils and demons, he exhibits cunning but not much intelligence. Regardless of his disguise, his big bare buttocks are always on display, often mooning the other characters. The names he assumes in his disguises reflect that fact, for example Officer Pantsoffski, Mrs. Barederrière, and Dr. Laxslax.
Personality
The Red Guy exhibits numerous strange behaviors, ranging from walking on his buttocks or rolling from side to side, to his almost bipolar moodswings. He acts both masculine and feminine, and likes to set himself up as an authority figure. He enjoys causing mischief, chaos, mayhem, pandemonium, and general nastiness: he is probably best described as a diabolical, mean-natured, and inconsiderate trickster in terms of villainy - not seeming to want much in the way of conquest or ruin but rather taking a perverse joy out of being a general nuisance and bully. Sadly for him, he is quite amateurish and incompetent, so he often ends up as little more than an irritation to Cow and Chicken.
It is also worth noting that the Red Guy likes to walk around nude and goes to great lengths to stay nude.
Role in the Series
Red Guy's schemes are intended to terrorize Cow, Chicken, Weasel, and Baboon for reasons never revealed (with Chicken being his favorite target of the four). These schemes are usually very bizarre and unorthodox, and usually involve masquerading as something he isn't, for example posing as a plastic surgeon or pediatrician, minus the pants. His schemes range from annoying or inconveniencing the heroes to outright trying to kill them.
He is often defeated by Supercow (a super-heroic persona taken by Cow) when his evil plans require foiling and Chicken needs rescuing. He tends to take his defeats in stride, though.